Very experienced interviewers.
They asked and talked about detailed questions, mostly about optical design, control of hardware, LiDAR systems, and time-of-flight measurement. Each interviewer had one specific area of focus, probably based on the projects they are currently working on.
It looks like Apple is making efforts in autonomous cars and Face ID, et al.
Not available due to confidentiality.
The following metrics were computed from 126 interview experiences for the Apple Hardware Engineer role in United States.
Apple's interview process for their Hardware Engineer roles in the United States is very selective, failing most engineers who go through it.
Candidates reported having very good feelings for Apple's Hardware Engineer interview process in United States.